Air circulation systems, for example, air conditioning and heating systems in buildings and aircraft, have been known to circulate airborne viruses and bacteria, spreading sickness to the occupants. This is becoming a concern to both the manufacturers of such systems as well as the occupants. Some air circulation systems in buildings are beginning to address this problem by including an air sterilization system therein for sterilizing the air. Typically, in such systems, the air is sterilized by irradiating the circulating air with ultraviolet lights. A drawback of this method is that the sterilization process is dependent upon the time of exposure to the ultraviolet light, and therefore, the effectiveness decreases with increasing air velocity. In addition, dust collecting on the ultraviolet lights reduces the intensity of the ultraviolet light that irradiates the air, which further reduces the effectiveness of the sterilization process.
The present invention provides a system for sterilizing air that is more effective than prior methods, and includes a duct for flowing the air therethrough. A first electron beam generator is positioned relative to the duct for irradiating the air flowing therethrough with a first electron beam. The first electron beam disables or kills microorganisms within the air such as viruses, bacteria, fungi, etc., to sterilize the air.
In preferred embodiments, an air circulator for causing air to flow through the duct can be included. In addition, the system can be in or form an air circulation system. A converter is positioned within the duct downstream from the first electron beam generator for converting ozone within the air into oxygen. In one embodiment, a reflector is in the duct opposite to the first electron beam generator for reflecting the first electron beam. In another embodiment, a second electron beam generator is positioned relative to the duct opposite to the first electron beam generator for irradiating the air flowing through the duct with a second electron beam. In yet another embodiment, the duct has two right angle turns on opposite sides of the first electron beam generator for providing shielding from radiation. This duct can be collimated.
The present invention is also directed to a method of sterilizing air which includes flowing the air through a duct and irradiating the air flowing through the duct with a first electron beam from a first electron beam generator. The first electron beam disables microorganisms within the air to sterilize the air. The sterilization can occur in an air circulation system.
Additionally, the present invention is directed to a method for sterilizing air including flowing the air through a duct and irradiating the flowing air with opposed first and second electron beams from first and second electron beam generators for disabling microorganisms in the air. The first and second electron beam generators are positioned relative to the duct opposite from each other.
The present invention is further directed to a method of sterilizing air including directing an electron beam into a sterilization chamber. The air is directed into the sterilization chamber generally against the direction of the electron beam and is redirected generally along the direction of the electron beam for irradiating the air and disabling microorganisms in the air.
The use of an electron beam to sterilize air in the present invention provides more effective sterilization of flowing air than prior methods such as irradiation with ultraviolet light because electron beams can disable or kill microorganisms more rapidly. In addition, electron beams are affected by dust to a lesser degree than ultraviolet light. Consequently, the present invention can effectively sterilize air flowing at high flow rates.